KR20060013596A - A structure of the ac driven plasma device for the flat lamps and fabrication thereof - Google Patents

Abstract

The present invention relates to an AC plasma element for a planar lamp used in a backlight or a planar light source, and a method for manufacturing the same. The present invention relates to cutting and molding a front glass substrate and a back glass substrate to have grooves having a predetermined interval. It can withstand atmospheric pressure when discharging the discharge cells without making the device mechanically durable, and it is possible to obtain a uniform brightness without installing a separate light diffuser plate. It relates to a method for producing.

Planar lamps, plasma elements, transparent electrodes, metal electrodes, grooves, fluorescent layers, discharge cells

Description

AC driven plasma device for flat lamps and method for manufacturing the same {A structure of the AC driven plasma device for the flat lamps and fabrication             

1 is a cross-sectional view of a conventional AC drive plasma element (element 1) for a planar lamp.

FIG. 2 is a plan view of the shaded portion in driving the element as viewed from the front of the element 1 without the light diffusion plate; FIG.

3 is a cross-sectional view of another conventional AC drive plasma element (element 2) for a flat lamp of another form;

Figure 4 is a plan view of the shaded portion when driving the device viewed directly from the front of the device 2 without the light diffusion plate.

5 is a cross-sectional view of an AC driving plasma element for a flat lamp according to one embodiment of the present invention.

6 is a plan view of a cross-sectional view for explaining one embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1,1 ': front glass substrate 2,2': transparent electrode

3,3 ': fluorescent layer 4,4': back glass substrate

5,5 ': metal electrode 6: white dielectric

6 ': transparent dielectric 7,7': encapsulant

8,8 ': discharge cell 9,9': spacer

10 visible light 11: light diffusing plate

11 ': Home

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an AC-driven plasma element for a flat lamp used as a backlight for an LCD (Liquid Crystal Display), an illumination light source, and a manufacturing method thereof, and more particularly, to a front glass substrate and a rear surface of a liquid crystal display. The glass substrate is cut or molded to provide grooves at regular intervals on the transparent electrode and the metal electrode, and a fluorescent film is formed to ensure durability of the device without installing a separate spacer and without installing a separate light diffuser plate. It is an object of the present invention to provide an AC driving plasma device for a flat lamp that ensures uniform brightness of the device.

Conventionally, as shown in FIG. 1, the structure of an AC driven PDP element used as a backlight and an illumination light source of an LCD is composed of an upper plate and a lower plate. The top plate is a planar transparent electrode (2) formed on the front glass substrate (1) by vacuum deposition and a thick, red, blue, green or white fluorescent layer printed on the opposite side of the transparent electrode to emit white light during gas discharge. 3) consists of. In this case, since the front glass substrate 1 is positioned under the transparent electrode 2, the front glass substrate 1 also serves as a dielectric in a capacitor such as a PDP device.

The lower plate restricts the current flowing through the device by accumulating charge during alternating current with the metal electrode 5 having silver paste or the like formed by a thick film printing method on the rear glass substrate 4, and also effectively reflects white light to prevent the front glass substrate 1. It is composed of a white dielectric material 6 having a high light reflectance printed on the thick film and a red, blue, green, or white fluorescent layer 3 formed by thick film printing on the white dielectric material 6 for export. The upper plate and the lower plate are melt-bonded by the encapsulant 7 containing frit glass as a main component to form discharge cells 8 through which gas discharge can occur. After degassing the air in the discharge cell 8, a mixed lamp such as argon (Ar), helium (He), neon (Ne), xenon (Xe), mercury (Hg), and the like is injected into the discharge cell (8) The PDP element for use is completed. When the air in the discharge cell 8 is drawn out, the front glass substrate 1 and the rear glass substrate 4 are subjected to a large force by atmospheric pressure, and may be bent or broken, thereby preventing a circular or plate-shaped spacer. (9) is dispersed in the discharge cell (8).

When an alternating current of several tens of KHz and several hundred volts is applied between the electrodes 2 and 5 of the completed PDP element, ultraviolet rays are generated from the discharge gas in the discharge cell 8 by the discharge phenomenon. The fluorescent layer 3 is excited by the generated ultraviolet rays, and white visible light 10 is emitted to the outside of the front glass substrate 1.

However, such a conventional flat lamp PDP device (element 1) has no complicated process due to its complicated process, and when the diameter and thickness of the scattered spacer 9 are not uniform, the spacer 9 is discharge cell 8. Rolling or sliding inside the shell caused fatal damage to the applied fluorescent layer 3, resulting in a decrease in quality and yield.

In order to solve this disadvantage, the spacer 9 is fixed onto the fluorescent layer 3 using an adhesive, but the process is difficult and the spacer 9, the white dielectric 6 and the metal electrode 5 are fixed. There is another problem that impurity gas may be generated during gas discharge from the gas, resulting in a decrease in brightness or lifetime.

However, the biggest disadvantage of the planar lamp PDP device is the shadow 9A which appears due to the spacer 9 installed in the discharge cell 8 as shown in FIG. 2 when driving the device, and reduces the uniformity of luminance generated by the device. In order to remove the floating shadow 9A, as shown in FIG. 1, the light diffusion plate 11 is provided to disperse the light.

The flat lamp PDP device (element 2) shown in FIG. 3 is another type of device developed to reduce manufacturing costs by improving the manufacturing process of the flat lamp PDP device shown in FIG. It has a structure of substrate / transparent electrode / protective film / discharge cell / phosphor / back glass substrate / metal electrode.

The transparent electrode 2 'is formed by depositing thousands of angstroms of indium tin oxide (In ₂ O ₃ : Sn) on the front glass substrate 1 having a thickness of several mm by vacuum deposition. A thick dielectric film 6 'is formed on the transparent electrode 2' to limit the current at the time of alternating current driving, and thousands of angstroms of magnesium oxide (MgO) is deposited by vacuum deposition to form a protective film 6 ". The calcium (MgO) protective film 6 "serves to prevent abrasion of the transparent dielectric material 6 'by ions generated during gas discharge.

On the other hand, aluminum (Al) having good reflectance of light on the glass of the same material as that of the front glass is deposited by thousands of angstroms by vacuum deposition to form the metal electrode 5 '. The back glass substrate 4 'on which the metal electrode 5' is formed is cut by a sandblasting method or a photolithography method by cutting the glass on the opposite side where the metal electrode 5 'is formed by about several mm in depth to form a groove 11'. After that, the fluorescent layer 3 'is formed inside the cut groove 11' by thick film printing or spraying, and then fired. The fabricated front glass substrate 1 'and the rear glass substrate 4' are thick film printed with encapsulant 7 'whose frit glass is the main component, followed by melting and bonding in an electric furnace. Exhaust the discharge cell 8 'of the bonded display board and inject dozens or hundreds of torr of mixed gas such as argon (Ar), helium (He), neon (Ne), xenon (Xe), mercury (Hg), etc. When an alternating voltage of several tens of KHz and several hundred volts is applied between the transparent electrode 2 'and the metal electrode 5', ultraviolet rays are generated from the injected mixed gas, and the fluorescent layer 3 'is excited by the ultraviolet rays, thereby causing visible light. You get (10).

The improved flat lamp PDP device has the same characteristics as the conventional PDP device because the metal electrode 5 'is formed outside the rear glass substrate 4' and the rear glass substrate 4 'itself acts as a dielectric. There is no release of impurity gas from the white dielectric 6 and the metal electrode 5, resulting in a long service life and no need for the white dielectric 6, thereby reducing manufacturing costs. At the same time, since the glass spacer 9 'is made by itself when the cutting groove 11' is formed, the spacer 9 shown in the conventional device 1 is unnecessary and various problems associated with it are solved.

However, as shown in FIG. 4, the element 2 is formed on the glass spacer 9 'except for the discharge cell 8' at the time of driving the element due to the glass spacer 9 'formed by itself in the process of cutting or forming the glass. The shadow 9B that is generated cannot be avoided. In order to remove this shadow 9B, the light diffusing plate 11 is necessarily required in the element 2 as in the element 1.

The present invention has been made to solve the problems of the conventional devices 1 and 2 as described above, in the construction of an AC-driven plasma device for a flat lamp, both the back glass substrate and the front glass substrate by cutting or molding the unevenness It is to provide an AC-driven plasma element for planar lamps, which provides mechanical durability and uniformity of luminance without installing a spacer and a light diffusion plate by forming a groove and forming a fluorescent film therein.

As shown in FIG. 5, the transparent electrode 2 'and the fluorescent layer 3' are formed on and under the cut or molded front glass substrate 1 ', respectively. A metal electrode 5 'is formed under the rear glass substrate 4', and a fluorescent layer 3 'is coated on the back glass substrate 4' to have a simple structure bonded by the encapsulant 7 '. And the white dielectric 6 and spacer 9 have structural features omitted.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The front and back glass substrates having a thickness of 2 to 4 mm are cut or formed into grooves parallel to the transparent and metal electrodes having a length of 1 to 3 mm.

Preferably, the glass having a thickness of 3 mm is dug a deep groove 11 'having a depth of about 2 mm by a sandblasting method or a molding method, and a groove between grooves of about several hundred microns. The glass spacer 9 'is formed.

Indium tin oxide (In ₂ O ₃ : Sn) on the front glass substrate 1 'made as described above was deposited by thousands of angstroms by vacuum deposition, and then a transparent electrode having a width of about several millimeters by photolithography or sandblasting. (2 '). Alternatively, the transparent electrode 2 'is directly formed by vacuum deposition using a metal mask having a width of about several mm on the windshield. The groove 11 'is formed by forming a red, blue, green, or white fluorescent layer 3' by thick film firing in a thickness of thousands of angstroms by screen printing or spraying.

On the other hand, aluminum (Al) having good reflectance of light is deposited on the rear glass substrate (4 ') made of the same method as the front glass substrate by vacuum deposition method, and thousands of angstroms are deposited by photolithography or sandblasting. A metal electrode 5 'having a width is formed. Alternatively, a metal mask having a width of about several mm is covered on the back glass to form the metal electrode 5 'directly by vacuum deposition.

The formed grooves 11 'are coated with a fluorescent layer 3' by a screen printing method or a spraying method on the order of several mm in width and several tens of microns in thickness, and then fired to produce a lower plate.

The upper and lower plates are manufactured by thick-printing the encapsulant 7 ', which is mainly composed of printed glass, and then overlaps the front glass substrate 1' and the rear glass substrate 4 'and melt-bonds them in an electric furnace.

Exhaust the discharge cell (8 ') of the bonded electronic display plate and injects a mixed gas composed of argon (Ar), helium (He), neon (Ne), xenon (Xe), mercury (Hg), and dozens to several hundred Torr When an alternating voltage of 30 KHz is applied about 500 V between the transparent electrode 2 'and the metal electrode 5', ultraviolet rays are generated from the injected mixed gas, and the fluorescent layer 3 'is excited by the ultraviolet rays, thereby causing desired visible light. You get (10).

The present invention replaces the spacer 9 and the light diffusion plate 11 of the existing device by cutting or molding the front and back glass substrates. Particularly important light diffusing plate replacement effects are explained as follows.

광선이 유리 간격재(9')를 통과하게 된다. As shown in FIG. 6, a deep groove 11 'is formed in the front glass substrate 1' to enlarge the discharge cell 8 ', thereby forming a fluorescent layer 3' formed in the groove 11 'of the front glass substrate and the rear glass substrate. ) Is bent inward rather than when it enters the glass spacer 9 'according to Snell's law.

Light rays pass through the glass spacer 9 '.

Therefore, shadows appearing in the conventional devices 1 and 2 do not occur, and as a result, the light diffusion plate 11 is not necessary.

In addition, both the transparent electrode 2 'and the metal electrode 5' are formed outside the discharge cell 8 ', and the transparent dielectric 6' and the white dielectric 6 are replaced by utilizing the glass itself as a dielectric material. The manufacturing process and manufacturing costs can be reduced. At the same time, there is an additional effect of extending the life of the device by reducing the impurity gas generated from these materials to the discharge cells 8 '.

Devices fabricated in this way do not use separate spacers, dielectrics and light diffusers, reducing manufacturing costs by less than twice.

In addition, the front and rear glass substrates 1 'and 4' maintain the form of an integral pier structure, and thus have a rigid structure that can withstand the glass substrate at atmospheric pressure.

Claims (3)

A groove having a thickness of 2 to 4 mm and a groove parallel to the metal electrode and a transparent electrode having a front glass substrate and a back glass substrate cut or molded are formed at a depth of 1 to 3 mm, and a fluorescent layer is thickly baked on the bottom of the formed grooves to discharge. A method of manufacturing an AC driven plasma element for a flat lamp, characterized by forming a cell. The method of claim 1, wherein the transparent cell or the metal electrode is formed outside the front and rear glass substrates in forming the discharge cell. A method of manufacturing an AC drive plasma element for a planar lamp manufactured by the method according to claim 1 or 2.

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